The present invention relates generally to the field of telecommunications and, in particular, to a system and method for transmitting data.
Consumers have an insatiable appetite for information and entertainment, colloquially referred to as xe2x80x9ccontent.xe2x80x9d This can be seen in the popularity of television, the internet and other content based media that are delivered to subscribers or users over various xe2x80x9cpipelines.xe2x80x9d A pipeline is a system that transmits data from a content provider, e.g., television station, website on the internet, etc., to a subscriber. For example, internet service providers such as AmericaOn Line use the telephony system as a pipeline to transmit information to its subscribers. The subscribers use a computer modem to dial-in to an internet service provider. Once on-line, the subscribers have access to various content providers (websites) and can download or upload information. Unfortunately, this is often a slow and cumbersome technique for conveying large quantities of data because the telephony system has transmission speed and bandwidth limitations. Certain subscribers have installed specialized high-speed telephonic connections, but the practice is not widespread because of the prohibitive costs.
Similarly, various conventional pipelines deliver video information from content providers with varying degrees of success. Conventionally, television stations use a wireless pipeline for delivering content to users. The television stations simply broadcast signals in a dedicated portion of the electromagnetic spectrum. Users access the signals with roof-top antennas. Cable systems are also used in many areas. These systems use coaxial cable to deliver video with increased quality and quantity directly to a user""s home or premises. However, conventional cable systems do not allow for interactive feedback to the content providers over the cable system. Retrofitting the existing cable systems with this feature will be expensive and time consuming.
In recent years, the industry has developed another broadcast based pipeline for delivering video data to end users. This system is commonly referred to as xe2x80x9cwireless cable.xe2x80x9d Wireless cable transmits microwave signals to subscribers from a central transmitter. The subscribers receive the signals with a microwave antenna that is placed on the roof-top of the subscriber""s premises and aimed at the central transmitter.
A main drawback to the wireless cable systems is that there is a limited frequency spectrum that is available. Further, consumers desire to have access to interactive services over this pipeline. Some wireless cable systems have dabbled with providing two-way communication over their wireless cable systems. However, developers are left with the task of increasing the capacity of this pipeline by more efficiently using the limited spectrum that is available.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for a transmission system that efficiently uses the assigned spectrum and allows for bidirectional communication.
The above mentioned problems with transmission system and other problems are addressed by the present invention and which will be understood by reading and studying the following specification. A transmission system is described which provides a more efficient use of assigned spectrum while allowing bi-directional communication.
In particular, an illustrative embodiment of the present invention provides a transmission system that communicates data to a number of subscribers. The transmission system includes a transceiver that has a number of highly directional antennas. A number of digital repeaters are disposed in a geographic region serviced by the transceiver. The repeaters include a sectorized antenna that communicates with subscribers in a number of sectors of the geographic region of the repeater. The repeater also includes an upstream demodulator/modulator circuit. The upstream demodulator/modulator circuit demodulates data from signals from subscribers that were modulated with a first modulation technique, and generates a re-modulated signal with the data using a second modulation technique. The second modulation technique is different from the first modulation technique such that the signals from the subscribers from the number of sectors are combined in the re-modulated signal so as to increase the capacity of the transmission system. The digital repeaters also include a highly directional antenna, that is coupled to the demodulator/modulator circuit and that communicates the re-modulated signal to the transceiver.